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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

27135 results found.

  1. GRB 000408, optical observations
  2. GRB 991208, UBVRI field photometry
  3. GRB000408, lotis optical observations
  4. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  5. GRB000301C - Addendum to GCN 623
  6. GRB 000323, optical observations
  7. GRB 000326: Optical Observations
  8. GRB000326, Radio observations
  9. GRB000313, Radio observations
  10. GRB 000313 - optical transient in the BATSE error box
  11. GRB 000307, Optical Observations
  12. GRB 000307, BVRI Field Photometry
  13. GRB 000301C: A Precise Redshift Determination
  14. GRB 000301C, Optical Observation
  15. GRB 000301C: HST/STIS CCD Imaging of the field
  16. IPN error box for GRB000307
  17. GRB000301C, optical R-band observations
  18. GRB 000301C Optical Observations
  19. GRB 000301C: K' Observations
  20. GRB000301C OT candidate optical observations
  21. GRB000301C - Host galaxy not detected in R (?)
  22. Optical observations of GRB000301c
  23. GRB000301C, Radio observations
  24. GRB000301C, Radio observations
  25. GRB000301C, near-infrared observations (JHK' imaging)
  26. GRB 000301c near-IR observations
  27. GRB 000301C, UBVRI field photometry
  28. GRB 000301C: OT confirmed
  29. GRB000301c optical observations
  30. GRB000301C, optical observations
  31. GRB000301C
  32. GRB 000301C : Optical Candidate
  33. GRB000301C: RXTE/ASM and IPN localizations
  34. GRB000226 [IPN Position]
  35. HST Observations of GRB 990712
  36. GRB 000214 near-IR observations
  37. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  38. GRB000210, Radio Observations
  39. GRB 000115, BVRI field photometry
  40. GRB000214: BeppoSAX GRBM and WFC Detection
  41. Optical observations of GRB000210
  42. GRB000210 X-ray afterglow
  43. GRB000214: X-ray afterglow candidate
  44. GRB000214 refined BeppoSAX-WFC position
  45. GRB 000210: BATSE Observations
  46. Optical observations of the Chandra X-ray source for GRB000210
  47. GRB000210, Radio Observations
  48. IPN triangulation of GRB000210
  49. GRB000210: possible afterglow detection with BeppoSAX NFI
  50. GRB000201, Radio Observations
  51. GRB000210: BeppoSAX GRBM and WFC Detection
  52. SAX_WFC_GRB_NOTICE
  53. SAX_WFC_GRB_NOTICE
  54. GRB000201 Optical Observations
  55. GRB 000201: TAROT optical observations
  56. GRB 991208, radio observations
  57. BATSE+IPN location of GRB000131
  58. IPN localization of GRB000131
  59. GRB 000126, optical observations
  60. BATSE Observations of GRB000115
  61. Second RXTE Observation of GRB 000115
  62. GRB991216, UBVRIJHK field photometry
  63. GCN resumes full operations
  64. GRB 991216 VLBA Observations
  65. GRB 991216: J band spectrophotometry
  66. GRB 991216: Detection of the Host and/or Absorber Galaxy
  67. IPN localization of GRB991226
  68. GRB 991216 RXTE ASM Observations
  69. GRB 991216: Updated BATSE parameters
  70. GRB 991217 (SAX J2303.2+0015) Optical observations
  71. Chandra observation of the X-ray afterglow of GRB991216
  72. GRB 991216, optical observations
  73. GRB 991216 Optical spectroscopy/imaging
  74. SAX J2303.2+0015 Optical observations
  75. IR observations of GRB991216
  76. GRB 991217 (SAX J2303.2+0015) Optical observations
  77. GRB991216 Optical and infrared observations of Beethoven Burst
  78. GRB 991216 Radio Observations
  79. GRB 991208 Keck Spectroscopy
  80. GRB 991208 Infrared Detection
  81. GRB991216
  82. GRB 991216--Summary of RXTE Observations
  83. GRB 991216 Optical Observations
  84. GRB 991216, optical observations
  85. GRB 991208 SAO-RAS Spectroscopy
  86. SAX J2303.2+0015: an x-ray/GRB?
  87. GRB 991216, Optical Transient
  88. GRB991216 ('Beethoven Burst') B, R, and K Observations
  89. GRB991216, infrared observations
  90. GRB 991208 optical observations
  91. GRB 991216 Optical Observation
  92. GRB 991216: Extremely bright BATSE burst
  93. R-band Observations of GRB991208 at TNG
  94. GRB991208, optical observations
  95. GRB 991208, Optical Observation
  96. GRB991208, optical observations
  97. GRB 991208 optical observations
  98. Optical Observations of GRB991105
  99. GRB991106: BeppoSAX/BATSE results
  100. GRB991106, near-infrared observations

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